Shankar Narasimhan S

Water Distribution Networks in many rural areas supply water from storage reservoirs at the source of water to a group of villages through gravity or by pumping. Due to poor operational policies, they often fail to meet the demand of the beneficiary villages. This work proposes a rational technique for scheduling the supply in such networks to maximize the water delivered to the villages in an equitable manner. A secondary objective is to minimize the number of valve operations. The problem is formulated as a LP followed by an ILP. The parameters in the optimization problem are obtained by simulations of a well calibrated hydraulic model or experimental data if such a model is not available.

The nexus between water and energy reveals that transporting water for end use is a highly energy intensive operation. In this work we consider the optimal operation of a water distribution network consisting of pumps delivering water to different reservoirs, with each reservoir catering to a time varying demand. Pumps and ON/OFF valves are used as manipulated variables to minimize energy consumption while meeting the demand. Due to the nonlinear nature of the pump operating curve and the hydraulics, this results in a Mixed Integer Nonlinear Program (MINLP). We propose a three step decomposition approach to solve this problem efficiently. The applicability of this technique is demonstrated on a water network proposed for a municipality in India and the potential advantages are reported. We also compare the solution times required for the proposed technique and a standard solver and demonstrate the efficiency of the proposed approach.

Optimal operation of water distribution networks can be posed as a scheduling problem where the objective is to meet the time varying demand while meeting constraints on supply, pressure etc. In the present work, we propose a robust optimization problem to address uncertainty in the parameters of the model used for optimization. The resulting problem is a second order cone program that can be solved efficiently. The formulation ensures a high probability of meeting the demands, adding to the practical significance. Further, we provide the results of applying this technique on a laboratory scale water distribution network.

With the demand for water increasing rapidly, optimal operation of Water Distribution Networks (WDNs) is necessary to provide consumers with the maximum amount of water possible in an equitable manner. This paper presents the outcomes of an experimental investigation of supply policies implementable on rural WDNs. Tests conducted on a fully automated lab scale network, configured to represent rural WDNs, shows significant variations in supply time with the operational policy followed. Further, a systematic set of experiments are carried out to determine the flow rates in different network configurations and this data is later used to formulate a linear programming problem that identifies an optimal operational policy for the system.